D88: Add read support for multiple disks in one file.

[tdaede]

No description provided.

[keirf]

I'll think about how to integrate this. I'm not keen on multi-disk files (nor compressed disk files) as that's what filesystems and archivers are for. But we should be able to read existing multi-disk files for sure.

[keirf]

Do you have an example multi-disk D88 file to hand by the way?

[tdaede]

If you don't like changing the from_file signature you could also do this with the filename, e.g. disk.d88:0 (technically ambiguous but likely not a problem in practice). I also agree that this is a bad idea but I ran up against an in the wild example.

I can send it to you if you like but you can create your own simply by cat-ing two d88 files together.

[keirf]

I don't even have any d88 files to hand. Can you give a URL for some?

I'm thinking of extending the :: option syntax but it's not been used when reading existing image files before so it's actually a bit of work. But my.d88::index=1 (for example) would be quite clean.

[keirf]

This is basically done now in master using the ::index=N option syntax.

It's a bit convoluted because currently options get applied after the file is opened and parsed. Which is pretty dumb. There is more lifting to be done to be able to pass option lists either to __init__ or to the from_file and to_file constructors directly. When that's done, we won't need to parse all the disks in a file, and we can error on out-of-range index more quickly and cleanly.

[keirf]

By the way I also am missing test files for a range of other PC-98 formats you added. Like DCP for example, which I think has been broken for a while. Do you have some example images of each type you could upload for me?